1. Biology 201 Organism S&F Dr. Tony Serino
Tissues
Biology 201 Organism S&F Dr. Tony Serino

4. Tissues:
Are a group of cells and their associated extracellular substances which perform a specific task
Four basic types:
Epithelium –cover a surface
Muscular –able to contract
Nervous –initiate and conduct electrical signals
Connective –protect, support and bind all other tissues together

5. Epithelium
Cover a surface –this allows them to control absorption, secretion, act as barrier to external environment, and control surface properties, such as friction.
Named for surface cell shape:
Squamous = flat cell (tile like)
Cuboidal = cube (square in XS)
Columnar = tall rectangular
Named for cell thickness
Simple = single cell thick
Stratified = >1 cell thick

6. Epithelium anchored by Basement Membrane
Made of collagen fibers

7. Simple Squamous Epithelium
Flattened cells
Found in lining of blood vessels, wall of lung alveoli

8. Found in epidermis, lining of mouth, esophagus, vagina

9. -found in kidney tubules, ducts, ovary surface

10. Stratified Cuboidal Epithelium
-found in the lumen of large ducts of the salivary glands and some sweat glands

11. Simple Columnar Epithelium
-found in lining of GI tract, oviducts and small glands

12. -secretes mucous

13. Stratified Columnar Epithelium
-found in male urethra

14. Pseudostratified Columnar Epithelium
-appears stratified
-found in respiratory tract and male’s ducts

15. Pseudostratified Columnar Epithelium; Trachea

16. Transitional Epithelium
Able to change its stratification look
Thereby, thinning the organ’s wall
Found in urinary tract

17. Class Quiz on Epithelium

18. Muscular Tissue Ability to contract
Functions in body movements and movement of structures within the body
Three types:
Skeletal muscle
Cardiac muscle
Smooth muscle

19. Skeletal Muscle Voluntary –consciously controlled normally
Long, cylindrical, multi-nucleated cells
Has striations –due to arrangement of contractile proteins
Each cell directly connected to nervous system

20. Cardiac Muscle Involuntary –not under conscious control
Short, branched, single nucleated cells
Striated, spontaneous contraction
Cells act as syncytium –cells connected by gap junctions; therefore, one contracts, they all contract

21. Smooth Muscle -no striations -small spindle shape -single nucleus
-spontaneous contractions

22. Nervous Tissue
Initiates and conducts electrical signals (action potentials)
Coordinates all bodily functions
Forms mind, emotions: all higher functions
Responds to stimuli quickly
Consists of neurons and neuroglia cells

23. Neuron Structures
(Cell Body)
Initial Segment of Axon
(Nerve Endings)

24. Connective Tissue Protects, supports and binds all other tissues
Made of cells and extracellular matrix (which consists of ground substances (water, minerals, cell adhesion molecules, proteoglycans (with GAGs), etc.) and fibers (collagen and elastin)

25. Connective Tissues CT proper Loose Dense
includes areolar, reticular, elastic, and adipose
Connects tissues but allows space for cells to reside or pass through
Dense
includes dense regular and dense irregular CT
Matrix dominated by fibers (little empty space)
Dense regular CT is avascular

26. Loose Areolar CT Most abundant CT in body Found in most tissues
Fibroblast cells create and maintain the extracelluar matrix
Allows for the passage of nerves, blood vessels, etc.
Has mixture of collagen and elastin fibers

27. Reticular CT
Contains reticular fibers which are a thin form of collagen
Acts as the framework of organs
Created and maintained by fibroblasts

28. Elastic CT of an Artery
Elastin fibers dominate matrix and maintained by fibroblasts
Allows for great flexibility and elasticity
Spaces between fibers filled with other tissues
Found in large arteries, dermis, lungs, bladder

29. Adipose
Scattered throughout body but densely packed in certain regions such as subcutaneous layer of skin and on external surface of many organs
Little extracellular matrix
Functions as energy reserve and cushioning of internal components

30. Note how cytoplasm is moved to one side of large fat inclusion bodies.

31. Dense Regular CT
Fibroblasts secrete massive amount of collagen arranged in parallel bundles, little space in between
Avascular
Found in tendons, ligaments, organ capsules, sclera

32. Dense Irregular CT
Collagen fibers arranged in random fashion, leaving spaces for BV, nerves, etc.
Found in dermis of skin

33. Connective Tissue CT proper Cartilage
Consists of Chondrocytes in lacunae
Develop from Chondroblasts that are maintained at edge of tissue in a perichondrium layer
Both appositional (edge) and interstitial growth possible
Cartilage is dependent on surrounding tissue for nutrients through diffusion; it is avascular
Three types:
Hyaline Cartilage –more ground substance present
Elastic Cartilage –more elastin fibers present
Fibrocartilage –more collagen fibers present

34. Cartilage Avascular CT Appositional and interstitial growth possible
Perichondrium
Chondroblast
Lacuna
Chondrocyte
Matrix

35. Connective Tissue CT proper Cartilage Bone
Consists of osteocytes in lacunae
Develop from osteoblasts maintained in surrounding layer called periosteum
Formed into osteons (Haversian systems)
Highly vascular CT
Only appositional growth allowed

36. Bone

37. Connective Tissue CT proper Cartilage Bone Blood
Liquid CT (no fiber content, all proteins soluble in water)
Consists of RBCs, WBCs, and platelets (thrombocytes)
Developed from hematocytoblast

38. Blood
RBC
WBC
Platelet

39. Connective Tissue CT proper: Loose and Dense Cartilage Bone Blood
Embryonic CT –found mostly in embryonic stages
Mesenchyme –archetype cell for all CT (some persist as stem cells in the adult
Mucous CT –temporary CT found in umbilical cord

40. Identify this CT.

41. Identify this CT, it is the most abundant CT in the body.

42. Identify each type of muscle.

43. Identify the epithelium.

44. Identify the epithelium.

45. Identify the epithelium.